Last week and this week we have cleared 10 man Trial of the Crusader. The guest appearence of the Lich King when he shatter the floor and you drop down to Anub'arak is a nice touch I think, even though when it happened the first time I was out in the kitchen getting a cup of tea and came back just in time to watch our GM drown since he was afk. I must admit I was a bit confused about what had happened. At first I thought I thought the whole Argent Tournament had been flooded.
When it comes to the fights, the one we have had most difficulties with is the faction champions. I think it's the pvp element in that fight that takes some time getting used to if you are a pve player. As with pvp the champions gang up on players and they behave somewhat unpredictably and last week it took us a great many tries to get into the right "don't think so much, just concentrate on the right target and burn it down really fast while at the same time making it as difficult as you can for the others to hit or heal"-mood.
I think this fight is easier for healers than for the dps and tanks. As healer you just heal whatever you can, dispel whatever you can dispel and try to run away when the champions chase you and I generally have the feeling that even if healing of course is part of the success, this is not a blame the healer fight if you don't make it.
As for the twin valkyrs, the strategy that is most succesful for us is that everyone except one tank, that tanks healer and one more player (preferably a healer) pick the same colour and dps concentrate only on one twin. The only time the raid switch colour is when the twins do vortex of the opposite colour. After the vortex everyone switch back to the original colour they had and continue to dps the one twin. This way the twins will heal 20% when they do twins pact but if dps is high enough this won't be a problem and you don't loose time and dps with people running to change colour and changing twin to dps. The three players that had a different colour than the rest of the raid from the beginning stick to their colour too just like the others and for the two that are not tank their task is also to pick up the orbs in their colour so they don't hit other players. Best is to have one player on each side of the room for orb catching.
On general Jaraxxus I know many groups say you should spread out in a circle around the boss. For us it has been way more easy to stand in a semi circle on one side of the boss. This way everyone will be in range for healers and I think it's also easier for the OT to pick up the adds that way. My only wish in the Jaraxxus fight is that people wouldn't run away when they get the incinerate flesh debuff. Maybe it's the skull on the head that dbm puts up that scare people but please stand still so I can heal you instead of having to chase you across the room.